(2)A sentence of death may not be imposed upon a defendant convicted of a capital felony if it is determined in accordance with this section that the defendant has mental retardation.
(3)A defendant charged with a capital felony who intends to raise mental retardation as a bar to the death sentence must give notice of such intention in accordance with the rules of court governing notices of intent to offer expert testimony regarding mental health mitigation during the penalty phase of a capital trial.